The present invention relates to a process for producing a photo conductor drum unit to be used in image-forming devices such as laser printers and copiers, a process for producing an end member to be provided on the photo conductor drum unit, an end member, and a photo conductor drum unit.
A photo conductor drum is provided on image-forming devices such as laser printers and copiers. The photo conductor drum is a member for transferring contents to be represented, such as letters and graphics, to recording media such as paper. Such a photo conductor drum is composed by covering, with a sensitive layer, an outer circumferential surface of a conductive cylindrical substrate formed of aluminum or the like. The type of the photosensitive layer to be used for covering is appropriately selected depending on a device to which the photo conductor drum is applied.
On both ends of the cylindrical photo conductor drum, an end member for holding the photo conductor drum in an image-forming device and rotating the photo conductor drum around a cylinder axis. Therefore, the photo conductor drum is disposed in a state where the end member is mounted on both ends thereof as a photo conductor drum unit, in the image-forming device.
The end member is mounted to the photo conductor drum by inserting a part (fitting portion) of the end member into the inside of the cylindrical photo conductor drum and the outer surface of the fitting portion and the inner surface of the photo conductor drum are fixed with an adhesive.
Here, with regard to fixing of the substrate formed of aluminum or the like and the end member formed of a resin with an adhesive, there is a problem of adhesiveness such as exfoliation or durability against load torque (torque strength). One main cause for this problem is that there is an end member having a gear in combination and, in the case of a complex shape, it is preferred to use an easily formable resin but such a resin has a problem of adhesiveness attributable to compatibility with the adhesive.
From such a viewpoint, Patent Reference 1 discloses a technique of enhancing adhesiveness between the photo conductor drum and the end member. According to the technique, grooves are provided on the fitting portion beforehand at the time of producing the resin-made end member and the adhesiveness can be improved due to an anchoring effect.
Moreover, there is known a technique of fixing through mechanical “crimping” after the insertion of the end member into the photo conductor drum.
Furthermore, Patent References 2 and 3 disclose techniques of enhancing adhesive strength through roughening of the surface of the fitting portion by shot-blasting.
On the other hand, from the viewpoints of cost reduction, energy saving, and resource saving, it is required to reuse the end member.